public Triangle(double s1, double s2, double s3)
	{
		this.side1=s1;
		this.side2=s2;
		this.side3=s3;
	}
 
 
 
	public Isosceles( double EQside, double otherside)
	{
		super(EQside, otherside); //calls triangle constructor 
	}
 
 
	public Equilateral(double side)
	{
		super(side); //calls isosceles constructor. 
	}/

import java.util.ArrayList;
import java.util.List;

abstract class GeometricObject
{
	public abstract String perimeter();
}

class Triangle extends GeometricObject
{
	private double side1;
	private double side2;
	private double side3;
	public Triangle(double s1, double s2, double s3)
	{
		this.side1=s1;
		this.side2=s2;
		this.side3=s3;
	}
	public String perimeter()
	{
		return "Triangle's perimeter method";
	}
}
class Isosceles extends Triangle
{
	public Isosceles(double s1, double s2, double s3)
	{
		super(s1, s2, s3);
	}
	public String perimeter()
	{
		return "Isoceles Triangle's perimeter method";
	}
}
class Equilateral extends Isosceles
{

	public Equilateral(double s1, double s2, double s3)
	{
		super(s1, s2, s3);
	}
	public String perimeter()
	{
		return "Equilateral Triangle's perimeter method";
	}

}
public class Test
{
	public static void main(String... args)
	{
		List<Triangle> list = new ArrayList<Triangle>();
		list.add(new Triangle(0, 0, 0));
		list.add(new Isosceles(0, 0, 0));
		list.add(new Equilateral(0, 0, 0));
		for(Triangle t: list)
			System.out.println(t.perimeter());
	}
}

abstract class GeometricObject
{
	//signature for perimeter method
	public abstract double perimeter();
//begin class Triangle
public class Triangle extends GeometricObject
{
	//explicit constructor
	public Triangle(double s1, double s2, double s3)
	{
		this.side1=s1;
		this.side2=s2;
		this.side3=s3;
	}//terminates constructor
	//perimeter method
	public double perimeter()
	{
		return side1+side2+side3;
	}//terminates perimeter method
	//local data fields
	private double side1;
	private double side2;
	private double side3;
}//terminates text of class Triangle
//begin class Isosceles
public class Isosceles extends Triangle
{
	//constructor
	public Isosceles( double EQside, double otherside)
	{
		super(EQside, EQside, otherside);
	}//terminates constructor
	//local data fields
	private double EQside;
	private double otherside;
}//terminates class Isosceles
//begin class Equilateral
public class Equilateral extends Isosceles
{
	//constructor
	public Equilateral(double side)
	{
		super(side, side);
	}//terminates constructor
	//local data field
	private double side;
}//terminates class Equilateral

import Triangle.java.*;
import Isosceles.java.*;
import Equilateral.java.*;

public class Tester {
public static void main(String[] args) {
	Triangle tri = new Triangle(56,56,56);
	System.out.println(tri.perimeter());
	Isosceles iso = new Isosceles(56,56);
	System.out.println(iso.perimeter());
 
}
 
}